Refrigeration and ventilation device



NOV. 2, 1954 GREEN 2,693,088

REFRIGERATION AND VENTILATION DEVICE Filed Aug. 1, 1952 United States Patent REFRIGERATION AND VENTILATION DEVICE Frederick H. Green, Palos Verdes Estates, Califi, assignor to The Garrett Corporation, Los Angeles, Calif., a corporation of California Application August 1, 1952, Serial No. 302,270

19 Claims. (Cl. 626) This invention relates generally to a fluid conditioning apparatus and relates more particularly to refrigerating and ventilating apparatus.

While the invention has particular utility in apparatus for supplying air to certain types of flying suits for aircraft pilots and is hereinafter described and shown in connection therewith, it is to be understood that its utility is not limited thereto. Further, such suits may be broadly considered as enclosures.

The term aircraft, as used herein, may be considered to include various types of vehicles or devices which travgl through the earths atmosphere and, perhaps, beyon It is an object of the present invention to provide apparatus of the above character which will control the temperature and pressure of the air supplied to an enclosure and, hence, controls the temperature and pressure of the air in said enclosures.

Another object of the invention is to provide apparatus of this character having a separate control for the suit or enclosure.

Still another object of the invention is to provide apparatus of this character having modulating control means.

A further object of the invention is to provide apparatus of this character which will provide a relatively constant flow through said suit or enclosure.

A still further object of the invention is to provide apparatus of this character having a smooth temperature control.

Another object of the invention is to provide apparatus of this character which will prevent excessive suit pressure.

Still another object of the invention is to provide apparatus of this character adapted to minimize turbine back pressure.

A further object of the invention is to provide apparatus of this character which will operate without ram effect at the inlet of the heat exchanger.

Other objects and advantages of the invention will be brought out in the following part of the specification.

Referring to the drawing, which is for illustrative purposes only, there is schematically shown refrigerating and ventilating apparatus embodying the present invention.

Referring more particularly to the drawings, there is shown refrigerating and ventilating apparatus including a primary heat exchanger, indicated generally at 10, and a regenerator, indicated generally at 12.

Atmospheric air enters the heat exchanger by way of an inlet 13 and follows the course indicated by the arrows 14, said air being moved through the heat exchanger by means of a fan 16 at the end of said heat exchanger opposite the inlet 13 and such air is discharged to ambient atmosphere from the outlet 17. Air to be cooled is derived from any suitable source such as an engine supercharger or the compressor of a jet engine. This air is under pressure and is delivered to the heat exchanger 10 by way of aconduit 19 delivering said air to the inlet 19a of said heat exchanger, said conduit 19 having a shutoff valve 20 therein. The compressed air follows the path indicated by the arrows 21 through the heat exchanger and said air, when cooled, leaves said heat exchanger by way of conduit 24, the flow of cooled air being indicated by the arrows 25. Conduit 24 is connected with the inlet 26 of the regenerator l2 and may be further cooled therein. From the regenerator 12, the air is discharged from outlet 27 into conduit 28 2,693,688 Patented Nov. 2, 1954 which leads to the inlet of an expansion turbine 29. The turbine 29 is connected with the fan 16 by means of a shaft 30 whereby said fan is driven by said turbine. The turbine 29 discharges air into a conduit 31 which leads to a conduit 32 and the latter is connected with a suit 33.

There is a passage 35 which branches from the passage or conduit 28 and which is connected to the conduit 31. Passage 35 may be termed a bleed passage and is provided with a valve 37 for controlling the flow of air therethrough. The valve 37 is shown as a butterfly valve although any other type of suitable valve may be used. This valve is connected to and operated by a motor, indicated generally at 38, to which said valve is connected. Valve 37, during operation of the system, will be held in fully open or fully closed position. Movement of the valve between extremes is to be rapid. There also may be a valve 39 in the conduit 28 between the junction point 40 of said conduit with the conduit 35 and the turbine 29. Valve 39 is also shown as a butterfly valve although it may be of any other suitable type and is connected to and operated by a pressure responsive device, indicated at 41. Pressure responsive device 41 has a connection 42 with the conduit 31 so that outlet pres sure of the turbine 29 is transferred to said device 41 which operates in response to variations in the differential of pressure between turbine back pressure and ambient atmosphere.

The conduit 31 is provided with a check valve 45 between the junction 46 with conduit 35 and the turbine 29. Between said check valve 45 and turbine 29 is a branch passage or conduit 47 leading from said conduit 31 to the regenerator 12 for delivering cooled air to said regenerator, such air being discharged to atmosphere by way of the outlet 48. Air flow through conduit 47 is controlled by a valve 50 which is shown as being a butterfly valve although any other suitable type of valve may be used. Valve 50 is connected to and controlled by a motor which is indicated generally at 51.

Motor 38 is shown as being a reversible electrical motor having coils 53 and 54 for operating the motor in the valve closing and valve opening directions respectively and means for controlling the operation of said motor includes a pressure responsive switch, indicated generally at 56.

Switch 56 includes a movable contact member 57 operably engageable with a pair of fixed contact members 58 and 59 which are spaced apart from each other and are adapted to be respectively contacted by the member 57. Movable switch member 57 is connected to and adapted to be actuated by a pressure responsive device 69 which is shown as a bellows having its interior connected, by means of a conduit 61, to the inlet 19a of the heat exchanger 10 and having its exterior subjected to ambient atmospheric pressure so that said device is responsive to the differential of pressure between that derived from the compressed air source connected to the conduit 19 and ambient atmosphere. The movable contact member 57 is connected to a fixed contact N by means of a wire 62 which comprises one of the contacts of a manually controlled switch, indicated generally at 64. Switch 64 also has a fixed contact L connected by a wire 65 to the fixed contact 58 and the latter is connected with the coil 54 of a motor 33 by means of a wire 66. Switch 64 includes a third fixed contact H which is connected to the fixed contact 59 of switch 56 by means of a wire 67 and said contact 59 is connectedwith the coil 53 of motor 38 by means of a wire 68. in switch 64 which has a connection with a source of electrical energy by means of a wire 70, said source of electrical energy also includes a ground, not shown, and motor 38 is grounded at 71.

Motor 51 is also shown as a reversible electric motor and is provided with a pair of coils and 76 respectively for operating the motor in the valve closing direction and valve opening direction. Coil 75 is connected by a wire 77 with a temperature regulator 78 and coil 76 is connected with said regulator 78 by means of a wire 79. There are anticipators 80a and 80b in the conduits 24 and 31 respectively and a duct pickup 81a in conduit 31 or alternately 81b in duct 32 There is a movable contact member 69 3 and. said anticipators and picl-; -up a re connected by wires 84, 85, 86a and 86 to said temperature regulator 78 which controls the operation of motor 51 in accordance with the. rate of change. of temperature at anticipators 89a and/or Stlband .the temperature at pickup 31a or 81b. MotorSlis also grounded, at 87. .A temperature selector 89 is connected by means of..a .Wire 9 to. the temperature regulator 78, said. .selector89 being. located in any position so as to be, readily. accessible to adjustment by thepilot. the regulator'78 is fully disclosed in theBrown and Shank application for Electronicj Temperature Regulator, filed March .26, 1949, .Serial, No.'. 83,676, so that it is believed -to.be unnecessaryto go ..into.detail relativev to this part of the apparatus. in..this application.

A pressurized aircraft cabin is indicated ;generally at 95 and is provided with a suitable. sourceof air under pressure by any well-known means,.not shown. Cabin 95 is provided with a pressure regulator, 96, of any suitable well-known character so "thatthere willbe a} flow ofair through said cabin. The. pilot with his suit..33 is in 'the cabin95 and. said suit has outlet valve means shown as comprising .a..-plur.ality .of outlet valves197. Conduit 32, which leads to 'suit..33,. is: provided .with apressure control valve 99 adapted to regulate ithepressure to the suit and provide'thereto a, constant pressure. Upstream of the valve 99, they conduit 32 has a bleed connection 104 to a lower pressure region such as ambient atmosphere or the cabin, which connection is controlled by a manually operable valveiltll. lating valve 99-and the suit 33.is. a pressure .relief valve 1.02 discharging similarly into .a region of lower pressure. Between the pressure relief valve 102 and the suit is a manually operable shutoff valve 103 which may be controlled by the :pilot. The .unit shown and described herein supplied air only for the' pilots. suit and conditionedair for .the cabin or. pilot compartment is, in an installation of .this type, supplied by an entirely different. unit, not shown. Compressed air for the two systems may be supplied from the same sour e but the pressure required atthe outlet of the regeneration system supplying air to "the pilots suit, that is, at the inlet to the suit, ,is'ihigher than cabin pressure. The. temperatureof the air selected for delivery to the suit is also usually ditt erentjfromthe temperature of the air selected for delivery tow the cabin and, 'therefore, a separate temperature control system is used for the system supplying air to the suit. As shown herein, all the compressed air for the system passes through both the primary heat exchanger 1.0. and the regenerator 12. The path of flow of .the air. after it leaves the regenerator, is dependent upon whe herthe bypass valve 37 is in the open or theclosed position. As has already been stated, the pressure responsive valve mechanism 56, which controls the positioning of the valve 37, re-

sponds to variations in the. differential of pressure between that of the air. supplied to the system and ambient atmospheric pressure. It is to be. understood, of course, that other pressure diiferentials may be. emplo ed. j For example, between that of'th'e air supplied to the system and c bin pressure or the absolute pressure of the air supplied to the system may be used in controlling the position of the movable switch member 57.

The pressure of the air supplied to the system depends upon the altitude of the air ft and en ine speed. At low altitudes Where the differential between. the air supplied to the s s em and ambient pressure is greater than the diiferential for which the pressure responsive switch 56 is set, the bypass valve 37 will be closedand all of the air sup lied to the system will pass through the turbine 29. Part of the air leaving the turbine will flow through the conduits 31, check valve 45 and conduit 32 into the suit. Another portion of the air which passes through the turbine 29 flows through the branch passage 47, past valve 50;through the regenerator 12 and out to atmosphere. It is to be noted that air which passes from-the conduit 19 through the primary heat exchanger 10, conduit 24, regenerator 12 and turbine 29 undergoes cooling by said heat exchanger 10, regenerator 12 and turbine 29.

Control of the temperature of the air deliveredto the suit is eflected by positioning of the valve 50 which, in turn, is controlled by the actuating motor 51, the latter being under the control of the temperatureregulator 78 which, in turn, is set for the desired temperature by the Theconstruction and operation of Between. the reguthere may be used the ressure differentialv m nually. a tua ed. selec or ...89- ,The. regulator 57 -1 subject to a duct pickup control 81a or 8112 and also is subject to the rate of change anticipated control from the anticipators 80a and 80b. When the pilot selects the desired temperature on the temperature selector switch 89, which has an approximate rate of 50 F. to F., the system will then function to control the temperature of the air in accordance with" such selection at the pickup 31a or 81b.

Furthenmodulation is efiectedbymeans .ofgthe flow control valve 39 which is controlled by the pressure responsive device 41, the latter being sensitive to back pressure in the turbine outlet duct 31 and when that back pressure becomes greater than a predetermined amount above ambient, for example 5 p. s. i., the flow control valve 39 moves toward closed position for restricting flow to the turbine. This not only minimizes turbine backpressure but also .provides a smooth temperature control since it controls the totalflowand; therefore,v the energy delivered to the turbine and,-hence, the fan airflow through the primary heat exchanger it .The inlet 13 of the primary heat exchanger 10 is preferably .not subjected to ram effect. 5

When .the. airplane is flying at;.high altitude :or low speed at low altitudes where thegdiiferential' between the pressure of air delivered to the system and ambient pressure is less than the differential for Whichthe switch. .56 is. set, opening movement of the valve 37 will be, effected. When the latter valve opens, the check valveg45 will automatically close and the air inthe system will'follow the divided path provided at the dischargeend of the regenerator. .Some'of the air will-passthrough'the conduit 35, passage 32, through .the regulating valve 99 and, thence, to the suit 33. The balance of the. air from the regenerator will pass through the turbine 29, into conduit 31 and thence to branch conduit; 47, through the cooling passages of the regenerator 12 and thence to atmosphere. The suit during this phase of the operation receives air from the upstream side of.the turbine. 29 instead of the downstream side thereof. The temperature control system will still'operate as described above but its action on the air will be indirect, that is, through the regenerative heat exchanger, there being no. air flow directly from the turbine'to the suit.

When flying athigh altitude, the pressure required in the suit may .be almost as-great-as -the-pressure of the air'introduced into the system. In that case, the bypass valve 37 will be open so that the .air which passes through the regenerator 12 will flow through the conduit 35 and thence toconduit 32 and the suit. -Also opening of the valve 37 will increase the pressure drop across the turbine due to the fact that the air passing through the turbine will'now exhaust toambientatm'osphere. The increase in pressure drop across the turbine will provide a greater rop in temperature-of the air passingthrough the turbine.

Adjustment of the valveSl) in the conduit 47 will simultaneously efiect changes at the primary heat exchanger 19, turbine 29, and regenerator 12. For example, if the valve 50 is moved towards the closed position, the reduced amount of cooling air flowing through the regenerator 12. will result in an increase in the temperature of the airat discharge 27 of regenerator 12. Moreover, the closing of the valve'Stl will increase the back pressure at the turbine outlet, thereby reducing the pressure drop across the turbine and providing less temperature drop through the turbine. This will also effect reductionin the speed of the turbine which will, in turn, reduce-the speed of the cooling fan 16 in the primary heat exchanger lll'thereby drawing less air through said primary heat exchanger which will usually result in increasingthe temperature in conduit 25. It is to be noted that this same temperature control works whether the valve 37 is open or closed.

To safeguard the pilot from surges of excessively hot air, the temperature control valve 50 utilizes an extremely slow actuator so as to minimize hunting of the control elements in'the regenerative circuit. Another method of controlling the valve Sllis to provide anactuator which will effect quick opening'of the valve and slow closing thereof.

An additional safeguard is the provision of limit switches for the valve 50 mechanism which have been. adjusted so that the valve cannot close completely. Furthen'the temperature regulator'78-may be adjusted to give-very short pulses with dead bands as desired and separate modulation band settings on each side such that the current to the valve may always pulse and never become steady.

The pressure control valve 99 is shown as being installed within the pressurized cabin and is calibrated to maintain the suit inlet pressure at a predetermined pressure above cabin pressure, for example 5 p. s. i. at all times when sufiicient pressure is supplied to the valve. This constant differential gives a relatively constant flow through the suit. It is necessar of course, to maintain the pressure in the suit somewhat above the pressure of the region into which the suit exhausts.

It is to be understood that the suit, when worn by the pilot, is to be made air tight at the ankles, wrist and neck so that the only means of escape for the air in the suit is through the various outlet valves 97 of said suit.

The pressure relief valve res may be set for a predetermined pressure above the setting of the pressure control valve 99 and when this pressure is exceeded, air from conduit 32 is exhausted into the cabin to reduce pressure to the set value.

When starting, the valve 37 is open. It will not close until the differential between the pressure of the air supplied to the system and ambient pressure is greater than the diflferential for which the pressure switch 56 is set."

Should the pilot wish to close valve 37 when the automatic control mechanism therefor has the valve in the open position, the pilot can operate the manual controls to keep said valve closed. Switch 64 provides such manual control which will override the control of the pressure responsive switch 56. Alternatively, there may be a switch on the landing gear which, when the landing gear is in use, will maintain the valve 37 in the closed position.

Other manual. controls for the apparatus include the valve 103 which is manually operable for controlling flow into the suit in accordance with the desires of the pilot or other occupant of said suit. There is, of course, the manually controlled temperature selector device 89 which the pilot may also use in the control of the temerature of the air supplied to the suit. The valve 101 may be opened to permit air to bleed from the duct 32 into an unpressurized area and this valve may be used for test purposes or balancing of various components of the apparatus.

I claim:

1. Apparatus for conditioning compressed air from a source of compressed air to an enclosure, comprising: first cooler means having first and second passage means in heat transfer relation to each other; second cooler means having first and second passage means in heat transfer relation to each other; means for directing a flow of compressed air from said source through the first passage means of the first cooler means and thence to the first passage of the second cooler means; means for directing a flow of coolant through the second passage means of the first cooler means for cooling the compressed air flowing through the first passage means of the first cooler means; fan means for etfecting a flow of coolant through said second passage means of the first cooler means; an expansion turbine having an inlet and an ou let; means operably connecting said turbine with said fan; passage means connecting the second cooler means with the inlet of said turbine whereby compressed air passing through the second cooler means is conducted to said turbine; turbine outlet passage means connecting the outlet of said turbine with said enclosure; a turbine outlet branch passage connecting said turbine outlet passage means with the second passage means of the second cooler; a branch passage branching from the passage from the second cooler to the turbine and connected with the turbine outlet passage; a check valve in the turbine outlet passage upstream of the junction thereof with the second mentioned. branch pass go; valve means controlling the flow of air through said second mentioned branch passage; means for controlling said valve comprising pressure responsive switch means responsive to variations in the differential of pressure between that of the air supplied to the system at the first mentioned cooler means and ambient atmosphere; a valve controlling the turbine outlet branch passage; and temperature responsive means connected with the last mentioned valve means for controlling same.

2. Apparatus for conditioning compressed air from a source of compressed air to an enclosure, comprising: first cooler means having first and second passage means in heat transfer relation to each other; second cooler means having first and second passage means in heat transfer relation to each other; means for directing a flow of compressed air from said source through the first passage means of the first cooler means and thence to the first passage of the second cooler means; means for directing a flow of coolant through the second passage means of the first cooler means for cooling the compressed air flowing through the first passage means of the first cooler means; tan means for effecting a flow of coolant through said second passage means of the first cooler means; an. expansion turbine having an inlet and an outlet; means operably connecting said turbine with said fan; passage means connecting the second cooler means with the inlet of said turbine whereby compressed air passing through the second cooler means is conducted to said turbine; turbine outlet passage means connecting the outlet of said turbine with said enclosure; a turbine outlet branch passage connecting said turbine outlet passage means with the second passage means of the second cooler; a branch passage branching from the passage from the second cooler to the turbine and connected with the turbine outlet passage; a check valve in the turbine outlet passage upstream of the junction thereof with the second mentioned branch passage; valve means controlling the flow of air through said second mentioned branch passage; means for controlling said valve comprising pressure responsive switch means responsive to variations in the differential of pressure between that of the air supplied to the system at the first mentioned cooler means and ambient atmosphere; a valve controlling the turbine outlet branch passage; temperature responsive means connected with the last mentioned valve means for controlling same; and pressure regulating means in the connection to the enclosure for providing a substantially constant pressure to said enclosure.

3. Apparatus for conditioning compressed air from a source of compressed air to an enclosure, comprising: first cooler means having first and second passage means in heat transfer relation to each other; second cooler means having first and second passage means in heat transfer relation to each other; means for directing a flow of compressed air from said source through the first passage means of the first cooler means and to the first passage of the second cooler means; means for directing a flow of coolant through the second passage means of the first cooler means for cooling the compressed air flowing through the first passage means of the first cooler means; fan means for efiecting a flow of coolant through said second passage means of the first cooler means; an expansion turbine having an inlet and an outlet; means operably connecting said turbine with said fan; passage means connecting the second cooler means with the inlet of said turbine whereby compressed air passing through the second cooler means is conducted to said turbine; turbine outlet passage means connecting the outlet of said turbine with said enclosure; a turbine outlet branch passage connecting said turbine outlet passage means with the second passage means of the second cooler; a branch passage branching from the passage from the second cooler to the turbine and connected with the turbine outlet passage; a check valve in the turbine outlet passage upstream of the junction thereof with the second mentioned branch passage; valve means controlling the fiow of air through said second mentioned branch passage; means for controlling said valve comprising pressure responsive switch means responsive to variations in the differential of pressure between that of the air supplied to the apparatus at the first mentioned cooler means and ambient atmosphere; a manual override switch controlling said valve control means; a valve controlling the turbine outlet branch passage; temperature responsive means connected with the last mentioned vaive means for controlling same; pressure regulating means in the connection to the enclosure for providing a substantially constant pressure to said enclosure; and manually controlled valve means in said passage between the pressure relief means and said enclosure.

4. Apparatus for conditioning compressed air from a source of compressed air to an enclosure having valve controlled outlet means, comprisin first cooler means having first and second passage means in heat transfer relation to each other; second cooler means having first and second passage means in heat transfer relation to each other; means for directing a'flow of compressed air from said source through the first passage means of the first cooler rneansmnd to the-first: passage-of the second cooler means; -means fordirecting a flow of coolant through the secondpassage means ofthe first cooler means for cooling the compressed air flowing through the first passage means of the first cooler means; fan means for, effecting a flow of coolant through said second passage means of the first cooler means; an expansion turbine having an inlet and an outlet; means operably conmeeting said turbine with said fan; passage means connecting the second cooler-means with the inlet of said turbine whereby compressed air passing through the secondcooler means is conducted to said turbine; turbine outlet passage means connecting the outlet of said turbine with said enclosure; a turbine outlet branch passage connecting said turbine outlet passage means with the second passage means of the second cooler; a branch passage branching from the passage from the second cooler to the turbine and connected with the turbine outlet passage; a check valve in the turbine outlet passage upstream of the junction thereof with the second mentioned-branch passage; valve means controlling the flow of air through said second mentioned-branch passage; means for controlling said valve comprising pressure responsive switch means responsive to variations in the differential of pressure between that of the air supplled to the system at the first mentioned cooler means and ambient atmosphere; a manual override switch controlling said valve control means; a valve controlling the turbine outlet branch passage; temperature responsive means connected with the last mentioned valve means for controlling same; pressure responsive valve means controlling the passage from the second cooler means to the turbine inlet and located between the junction of the branch passage thereof and the turbine inlet, said pressure responsive valve means being responsive to variations in the differential of pressure between turbine back pressure and ambient atmosphere; pressure regulating means in the connection to the enclosure for providing a substantially constant pressure to said enclosure; pressure relief means in the passage to the enclosure, said pressure relief means being .located between the pressure control means and said enclosure; manually controlled valve means in said passage between the pressure relief means and said enclosure; and manually controlled bleed means adapted to connect the passage to the enclosure with atmosphere, said bleed means being connected with said passage upstream of said pressure regulating means.

5. Apparatus for conditioning compressedair from a source of compressed air to an enclosure, comprising cooler means having first and second passage means in heat transfer relation to each other; an expansion turbine having an inlet and an outlet; means for directing flow of compressed air from said source through the first passage means and to said turbine inlet; turbine outlet passage means connecting the outlet of said turbine with said enclosure; a turbine outlet branch passage connecting said turbine outlet passage means with the second passage means of said cooler means; a branch passage branching from the passage from said cooler to the turbine inlet, said branch passage being connected with said turbine outlet passage downstream of the point of connection with said outlet branch; a check valve in the turbine outlet passage between the junctions of said branch passages with said outlet passages; valve means controlling the flow of air through thesecond mentioned branch passage; means for controlling said valve comprising pressureresponsive switch means responsive to variations in the differential of pressure between that of the air supplied to the apparatus and ambient atmosphere; a valve controlling the turbine outlet branch passage; and temperature responsive means connected with the last mentioned valve means for controlling same.

6. Apparatus for conditioning compressed air from a source of compressed air to an enclosure, comprising: cooler means having first and second passage means in heat transfer relation to each other; an expansion turbine having an inlet and an outlet; means for directing flow of compressed air from said source through the first passage means and to said turbine inlet; turbine outlet passage means connecting the outlet of said turbine with said enclosure; a turbine outlet branch passage connecting said turbine outlet passage means with the second passage means of said cooler means; a branch passage branching from the passage from said cooler'to the turbine inlet,- said branch passage being connected with said turbine; outlet .passage downstream of the point; of ;connection-twith-said outlet branch; a checkwvalve 'inthe turbine outlet passage between the junctions of said branch passages with said outlet passages;-avalve controlling; the turbine outlet branchpassage; and temperature responsive means operably connected withv said valve and controlling same.

7. Inapparatus for conditioning a gaseous fluid which is conducted froma source of said'fluid to a-compartment: first cooler means having first and second passage means in heat transfer 'relation;.second cooler means having an inlet and an outlet; means directing a. flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet withsaid compartment; branch passagevrn'eans directing a flow of gaseous fluid from said outlet through said second means to cool the gaseous fluid which flows through the-first passage means; temperature responsive means controlling the flow of fluid through said br'anch passage means; and bypass passagemeans adapted. to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means,. said bypass passage means having an outlet connectionwith the outlet passage means downstream of said branch passage.

8. In-apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow ofwgaseous fluid from said source through. said first passage means to sa1d inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing aflow. of gaseous fluid from said outlet throughsaid second passage means to cool the gaseousfluidwhich flows through the first passage means; temperature respons1ve means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first coolermeans and the second cooler means, said bypass passage means havingan outlet connection with the outlet passage means downstream of said branch passage; and pressure responsive means controlling the flow of fluid through said bypass passage.

9. In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment:v first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means .to said inlet; outlet passage means connecting said outletwith said compartment; branch passage means directinga flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; means responsive to one of the characteristics of the fluid in the apparatus controlling the flow of fluid through said branch passage means; and bypass passage means adapted to re- C61V6, fluld from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outletconnection with the outlet passage means downstream of said branch passage.

l0.- In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first-cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow ofgaseous fluid-from saidsource through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which'flows through the first passage means; means responsive to a variable characteristic of the fluid in the apparatus controlling the flow of fluid through said branch passage means; bypass passage means adapted to receivefluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of saidbranch passage; and means controlling the flow of fluid through said bypass passage. i l1. In apparatus for conditioning a gaseous fluid which 1s-.conducted from a source oi said fluidto; a e m j hment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; temperature responsive means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; and pressure responsive means controlling the fiow of fluid through said bypass passage means.

12. In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; temperature responsive means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; pressure responsive means controlling the flow of fluid through said bypass passage means; and a pressurized enclosure, said compartment being located within said pressurized enclosure.

13. In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; temperature responsive means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; pressure responsive means controlling the flow of fluid through said bypass passage means; a pressurized enclosure, said compartment being located within said pressurized enclosure; and valve means for said compartment, said valve means opening when the pressure in said compartment is above a predetermined value.

14. In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; temperature responsive means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; and a check valve in the outlet passage means upstream of the junction of the bypass passage means with the outlet passage means.

15. In apparatus for conditioning a gaseous fluid which is conducted from a source of saidfluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; temperature responsive means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; and check valve means in the outlet passage means between the junctions of said branch passage and bypass passage with the outlet passage.

16. In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; temperature responsive means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; and pressure responsive means for controlling the flow of fluid to the second cooler means, said pressure responsive means being subjected to back pressure at the outlet of said second cooler means.

17. in apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outiet through said second passage means to cool the gaseous fluid which flows through the first passage means; means controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; and a check valve in the outlet passage means upstream of the junction of the bypass passage means with the outlet passage means.

18. In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an inlet and an outlet; means directing a flow of gaseous fluid from said source through said first passage means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage means directing a flow of gaseous fluid from said outlet through said second passage means to cool the gaseous fluid which flows through the first passage means; means responsive to one of the characteristics of the fluid in the apparatus controlling the flow of fluid through said branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means, said bypass passage means having an outlet connection with the outlet passage means downstream of said branch passage; and a check valve in the outlet passage means upstream of the junction of the bypass passage means with the outlet passage means.

19. In apparatus for conditioning a gaseous fluid which is conducted from a source of said fluid to a compartment: first cooler means having first and second passage means in heat transfer relation; second cooler means having an 1 1 inlet and an'dutlet; meansdirec'ting afioW ofgaseou's fluid from" said source' througIi said'first'pas'sag'e' means to said inlet; outlet passage means connecting said outlet with said compartment; branch passage ,me'ans directing a flow of gaseous fluid from said outlet through said second passage means to'cool the gaseous'fiuid which flows through the first'passagemeans; means controlling the flow of fluid throughsaid branch passage means; bypass passage means adapted to receive fluid from the first passage means and connected thereto between the first cooler means and the second cooler means said bypass passage 12 nie'hs hm/ing an u-ut 'c'orine'ct'ioWWith the outle't p'assage 'me'an's" downstrekar'n of said "branch passage; and-a checkva'lve in the fou'tlet passage means urged finthe-closlug-direction *by 'pr'es'sufe in said bypass'passag'emeans;

ReferencwCited 'in' the fileof this' paten't- UNITED STATESPA'TENTS Name 

